Q & A: Chewing and Spitting Out Food

Q. Is there a name for the eating-disordered behavior of chewing and spitting out food before swallowing? Is there any research on the prevalence of and association with other behaviors? Finally, how many calories are retained with this behavior? (M.K., Philadelphia)

A. As far back as 1985, Mitchell et al reported that 64.5% of a large series of patients with bulimia nervosa chewed and spit out food, and used other compensatory means of not retaining calories (Am J Psychiatry 1985; 142:482). Since that time, a number of case reports and small series have been reported on this common phenomenon. The most recent series, published by Robert Palmer’s group in Leicester, England, reported this symptom pattern in 22% of their eating disorder patients. They found that patients with anorexia nervosa and eating disorders not otherwise specified who reported chewing and spitting out food showed more severe eating-related pathology. This was not the case in patients with bulimia nervosa. In none of the patient groups was chewing and spitting out associated with the frequency or intensity of binge eating per se (Int J Eat Disord 2002; 32:112). Several clinicians, including myself, have observed these phenomena, and suggest that this pattern serves different psychological functions for different individuals. Often it helps satisfy various oral urges—needs to bite, masticate, and taste, with the additional clear goal of not ingesting the calories. I’m not aware of research showing how many calories may actually be retained in this practice. Undoubtedly it will vary with the type of food being chewed—how easily it’s liquefied, and how much unintentional swallowing actually occurs.

To my knowledge, this symptom pattern has no specific medical label, although the recent Leicester study used the acronym CHSP for “chewing and spitting out.” You’ve identified an “appellation niche” that scholars may wish to fill in future publications. Masticatoria Nervosa?